Thanks for some very interesting reading here. Just a couple of thoughts inspired by a few of your comments...

Quote

...talesin the sense of fictional compositions.

"Tales" in Middle-earth are never fictional really, are they? They are all "true", in the sense that they are attempts by the characters to put real (from their perspective), remembered events into words. I'm trying to think of any deliberate "fiction" in Middle-earth. Sam's song of the troll, perhaps?

Quote

I’m not sure you’re contrasting “prosy” and “prosaic” correctly. I think “prosy” in the narrator’s comment about Bilbo’s flight of poeticism about the fireworks is meant to convey the idea of plain speech. So despite his professions of being uninterested in adventures Bilbo is capable of picturesque rhetoric, i.e., romance and poetry even if rendered in prose (unversed speech). But to say that Bilbo’s father’s sayings are prosaic is simply to say that they are commonplace and well-known. It doesn’t mean they don’t have color and imagery – that’s exactly what they do have, and Bilbo’s fondness for them might suggest solidity and attraction to tradition, but it also might suggest an attraction to metaphor and imagery.

Nice argument! In fact, I don't think there's a clear line to be drawn between the forms of poetry and prose in Tolkien's writing - or even between the forms of 'speaking' and 'singing'. It's all one continuum, it seems to me, which is perhaps why "songs and tales" often go together as if they are just variants of the same thing. It's the content that matters, so as you say, anything with heightenend language ("picturesque rhetoric", "color and imagery", "metaphor") belongs to the category of "songs and tales", as opposed to the prosaic, superficial language that Gandalf calls Bilbo out for in the first chapter - phrases like "Good morning" and "I beg your pardon" that are ossified and meaningless - unless, like Gandalf, you take the trouble to look behind the cliche and dig out their real meaning. By that criterion, Bilbo's father's sayings could go either way - it all depends whether they are experienced as fixed formulas or living metaphors. As we see for example with Ioreth's "old wives' tale" about kingsfoil, one of Tolkien's little pleasures is in showing how a real, living meaning can be dug out of apparently dead old saws.

Quote

Well, he certainly never explains how the two different traditions both made it into print in the 20th century, when both are supposedly based on ancient sources edited by the same “discoverer”. In other words, Tolkien seems to want to differentiate between “There and Back Again” as a manuscript/book, which he found and edited first of all in the late 1930s; and the “Red Book of Westmarch” with Gondorian addenda, which he found and edited in the late 1940s and early 1950s. But in the LotR story (not the Hobbit story), the “Red Book” is “Bilbo’s Book”.

Here's one explanation (from the Prologue to LotR):

"This account Bilbo set down in his memoirs, and he seems never to have altered it himself, not even after the Council of Elrond. Evidently it still appeared in the original Red Book, as it did in several of the copies and abstracts. But many copies contain the true account (as an alternative), derived no doubt from notes by Frodo or Samwise, both of whom learned the truth, though they seem to have been unwilling to delete anything actually written by the old hobbit himself."

I don't imagine Tolkien the "translator/narrator" finding and editing two different books, but finding one collection of various manuscripts, perhaps bound together into a single "codex", that it took him years to figure out (including "translation" of this previously-unknown language, of course). So he started by translating what looked like a fairly self-contained story before going more deeply into the contents of the "book" and finding other versions of the same events as well as a lot of other context and backstory. (Although his hints in The Hobbit suggest that he'd already done some work on the bigger "legendarium" as well.) If you allow for the fact that medieval books are notoriously difficult to find your way through, consisting as they often do of assorted manuscripts in different hands and from different periods, all bound together, I think it's fair to cut Tolkien the scholarly "translator" some slack - there's enough stuff there to justify most of any ordinary scholar's career! They went in, and Sam shut the door. But even as he did so, he heard suddenly, deep and unstilled, the sigh and murmur of the Sea upon the shores of Middle-earth. From the unpublished Epilogue to the Lord of the Rings